Roof or floor construction



Nov. 27 1923 1,475,847

f H. E. MARKS I a V1 A f l INVENT/P MKM described Paten Nov. 27, i923.

UNITED STATES I. ERT

E. MARKS, 0F GLEN OSBOBNE, SEWICKLEY, PENNSYLVANIA.

B00? 0B FLOOR CONSTBU'CTON.

l application met December 15,1922. smal n. conoce.

To all whom t may concern:

Be it known that I, HERBERT E. Manns, a

citizen .of the United States, and a residentv of Glen Osborne,Sewickley, in the county of Allegheny and State of Pennsylvania, haveinvented a new and useful Improvement in Roof or Floor Constructions,which the following is a specification.

This invention relates to roof or door constructions in which the roofdecl: or floor is formed of cementitious material in the form of slabs,preferably pre-cast, and in which a metal mesh reinforcement, or' itsequivalent, is embedded in the cementitious material.

The object of the invention is to provide slabs for the purpose statedwhich cheapen the construction of roofs and floors, which insures thatthe metal reinforcement can be located well down in the tension zone ofthe slab but nevertheless completely protected against exposure, whichhave marked heat insulating properties, ceilings from sweating, andwhich'are per se waterproof on their upper surface.'

In the accompanying drawing Fig. 1 is a plan view, partly broken away,showing the invention applied to a roof construction; Fig. 2 is avertical sectional view taken on vthe line 2-2, Fig. 1'; and Fig. 3 is aview of a portion of Fig. 2 on enlarged scale, showing the preferredform of `metal reinforcement.

The drawings illustrate the invention applied to a roof construction,but it can be applied in any exactly similar way to a floorconstruction. In the drawings 1 represents the main beams of thestructure, which in the case of the roof will be the purlins. These maybe of any suitable type, either wood or metal, and are illustrated asmetal channel beams. 2 indicates the slabs which are shown of a lengthequal to the distance between adjacent purlins and are supported attheir ends u on the purlins, but which may be of any esired size andsupported in any desired way. These slabs are formed of three parte,to-wit, a lower facing portion 3, preferably formed by the well knownplaster or gypsum board, a member or body portion 4, formed of amaterial hereinafter and the metal reinforcement 5 embedded in the body4 near its lower surface and well do in the tension zone of the slab.

.proximately 10% thus preventing the a suitable bitumaterial, or soeither artiicial,

The body 4 is formed of mastic (bituminous mastic) called bitulithicconcrete, that is, formed by mixing together asphaltum with a suitableaggregate, such as sand, pebbles, or broken stone, in suitableproportions, but which preferably will be the natural rock asphalt foundin many parts of the count an which comprises the natural mixture o sandand a small percentage, ap-

of asphaltum.

These slabs will be formed in suitable molds', preferably by acold-pressing operation, although if desired the broken up rock asphaltmay be mildly heated before molding. The molding operation will beperformed in well known molding ways, by placing in the mold the plasterboard, the metal reinforcement, and the bitumastic material in properrelation to each other and then applying pressure to densify thebitumastic material and thoroughly bond the material together.Preferably a thin layer 9 of hot asphalt will be applied between theplaster board and the bitumastic material, in order to secure a strongerbond between the plaster board and the body of the slab. When thoroughlypressed the parts unite so thoroughly as to form substantially anintegral slab. The plaster board need not be placed in the bottom of themold, but the body of bitumastic material first formed therein underpressure and the face of plaster or gypsum formed thereon by pouring thegypsum up to the top of the mold, or the plaster board attached to thetop of the body by means of the binder, in either case the entire massbeing thoroughly bonded together so as to form a substantiallymonolithic structure.

The metal reinforcement may be of any kind, but is illustrated of aconstruction shown in and claimed in an application of even dateherewith, Serial No. 607,019, and comprising an electrically weldedfabric composed of longitudinal or strand wires or rods 6 and transversewires or rods 7 welded together at their crossing points, and so locatedin the slab that at one end thereof a transverse wire or rod 7 isoutside of and spaced from the end of lthe slab, while at lthe oppositeend of the slab the longitudinal thereof members 6 roject beyond the enthe slam a suitable d1stance, so that when or concrete upon the bodylll@ The slab described is per se Waterproei? end needs nolweterprooling coating applied to its top surface. llt is substantiallymonolithic sieb, The plaster on the under v surface imparts heatinsulating properties to the slab end prevents the ceiling fromsweating., ln addition, it insures that the metal reinforcement Wili notloe exposed on lower face of the slolo even though seid reinforcementslie located Well down toward the lower surface of the bitumastic loody.

The construction described is cheep on ac eount of the eheapness of vdiematerial used. which in its preferred form is e natural rock which needsonly to be crushed, and needs noheating to mold it into the slab,although a moderate heating may be resorted to, if desired? out will notmaterially add to the cost. When erticial bitume-.Stic materiel isemployed ti e percentage of loituminous constituent will be low,approximately that of the natural rock asphalt. rlhe slab is strong, hasgood weathering proper- 'ties and because of the low bituminous contentforms e ver' strong compression meniloer with substantially no slippagefactor; and this enables the metal reinforcement to effectivelystrengthen the slab. lrts natuy rel yf/aterproofing qualities melies itunneeessary to add the usuel suris r1on l., A for roof or doorconstructions comprising a plaster or gypsum looei'd forming1 its lowerJfece, a material molded thereto and integral thereA with,

2. slab :for roof or door constructions comprising e plaster or gypsumboard forming its lower :aee9 e body of bitumastio ineteiial, and eninterposed bituminous bond ing luyen l 3. A slab for root or oorconstructions comprising a lbody of bitumestic materiel, o, metalreinforcement emioedded in seid. loody in the tension zone thereofs enda lower faeing loonded seid loooly endlof'a material non-adherent to themold for forming the sleb. i

du slee for roof or door constructions comprising o bitunestic body, amotel reinforcement embedded therein and located iu its tension Zone, elower eeing; united to seid body by an interposed bituminous -loondinglayer end of' e material non-adherent to the mold in which the slab isformed. A slab for root oe floor constructions comprising e plaster orgypsum board forming its lower :facing5 e bonding coating of bituminousmaterial applied thereto, and e body of leituniostio materiel moldedunder pressure to nlastee or gypsum board.

ln testimony whereof, Ti sign my name,

nd e body of bitumastic`

